Before: November 28, 2017 Solve each system by graphing. 1. y = 2x – 1

Are You Ready? Solve each equation for x. y = 3x – 4 Simplify each expression. 2(x – 5) 12 – 3(x + 1) Evaluate each expression for the given value of x. 2/3x + 8 for x = 6

During: Solving Systems by Substitution Learning Target: I can… Solve systems of linear equations in two variables by substitution.

Sometimes it is difficult to identify the exact solution to a system by graphing. In this case, you can use a method called substitution.

The goal when using substitution is to reduce the system to one equation that has only one variable. Then you can solve this equation, and substitute into an original equation to find the value of the other variable.

Solving Systems of Equations by Substitution Know It! Solving Systems of Equations by Substitution Step 1: Solve for one variable in at least one equation, if necessary. Step 2: Substitute the resulting expression into the other equation. Step 3: Solve that equation to get the value of the first variable. Step 4: Substitute that value into one of the original equations and solve. Step 5: Write the values from Steps 3 and 4 as an ordered pair, (x, y), and check.

“I Do” Solving a System of Linear Equation by Substitution Solve each system by substitution.

“I Do” Solving a System of Linear Equation by Substitution Solve each system by substitution.

“We Do” Solving a System of Linear Equations by Substitution Solve each system by substitution.

“You Do” Solve each system by substitution 1. 2.

Sometimes you substitute an expression for a variable that has a coefficient. When solving for the second variable in this situation, you can use the Distributive Property.

“I Do” Using the Distributive Property Solve each system by substitution.

“You Do” Using the Distributive Property Solve each system by substitution.

Extra Practice: Solving Systems by Substitution Maze (You should have to work 11 problems)